Full-Polarimetric Radar

This application claims the benefit of priority to Taiwan Patent Application No. 113113890, filed on Apr. 15, 2024. The entire content of the above identified application is incorporated herein by reference.

Some references, which may include patents, patent applications and various publications, may be cited and discussed in the description of this disclosure. The citation and/or discussion of such references is provided merely to clarify the description of the present disclosure and is not an admission that any such reference is “prior art” to the disclosure described herein. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference.

The present disclosure relates to a radar, and more particularly to a full-polarimetric radar.

Existing multi-antenna radar technologies are all composed of same-polarized antennas, which have an issue of being unable to receive cross-polarization signals. Therefore, providing a radar capable of receiving cross-polarization signals for overcoming the above-mentioned disadvantage through improvement of antenna design and transceiver mechanism has become one of the important issues to be addressed in the related art.

In response to the above-referenced technical inadequacies, the present disclosure provides a full-polarimetric radar capable of transmitting and receiving cross-polarization signals.

In order to solve the above-mentioned problems, one of the technical aspects adopted by the present disclosure is to provide a full-polarimetric radar, which includes a first dual-polarized antenna module, a second dual-polarized antenna module and an antenna control circuit. The first dual-polarized antenna module includes a first polarized antenna and a second polarized antenna, the first polarized antenna has a first polarization port, the second polarized antenna has a second polarization port, and polarization directions of the first polarized antenna and the second polarized antenna are orthogonal to each other. The second dual-polarized antenna module includes a third polarized antenna and a fourth polarized antenna, the third polarized antenna has a third polarization port, the fourth polarized antenna has a fourth polarization port, and polarization directions of the third polarized antenna and the fourth polarized antenna are orthogonal to each other. The antenna control circuit is electrically connected to the first polarization port, the second polarization port, the third polarization port, and the fourth polarization port, and the antenna control circuit is configured to: control two mutually orthogonal ones of the first polarized antenna, the second polarized antenna, the third polarized antenna, and the fourth polarized antenna to radiate a first transmitting signal and a second transmitting signal that are mutually orthogonal at a first time point and a second time point, respectively; receive a first reflecting signal and a second reflecting signal that correspond to the first transmitting signal, and a third reflecting signal and a fourth reflecting signal that correspond to the second transmitting signal through another two mutually orthogonal ones of the first polarized antenna, the second polarized antenna, the third polarized antenna, and the fourth polarized antenna; and generate a detection result according to the first reflecting signal, the second reflecting signal, the third reflecting signal and the fourth reflecting signal.

In order to solve the above-mentioned problems, one of the technical aspects adopted by the present disclosure is to provide a full-polarimetric radar, which includes a plurality of dual-polarized antenna modules and at least one antenna control circuit. The plurality of dual-polarized antenna modules each includes a first polarized antenna and a second polarized antenna, the first polarized antenna has a first polarization port, the second polarized antenna has a second polarization port, and polarization directions of the first polarized antenna and the second polarized antenna are orthogonal to each other. The at least one antenna control circuit is electrically connected to the first polarization port and the second polarization port of each of the plurality of dual-polarized antenna modules, and the at least one antenna control circuit is configured to: control the plurality of dual-polarized antenna modules to radiate a first transmitting signal and a second transmitting signal; receive a first reflecting signal and a second reflecting signal that correspond to the first transmitting signal, and a third reflected signal and a fourth reflected signal that correspond to the second transmitted signal through the plurality of dual-polarized antenna modules; and generate a detection result according to the first reflecting signal, the second reflecting signal, the third reflecting signal and the fourth reflecting signal that are received.

These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure.

The present disclosure is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Like numbers in the drawings indicate like components throughout the views. As used in the description herein and throughout the claims that follow, unless the context clearly dictates otherwise, the meaning of “a,” “an” and “the” includes plural reference, and the meaning of “in” includes “in” and “on.” Titles or subtitles can be used herein for the convenience of a reader, which shall have no influence on the scope of the present disclosure.

The terms used herein generally have their ordinary meanings in the art. In the case of conflict, the present document, including any definitions given herein, will prevail. The same thing can be expressed in more than one way. Alternative language and synonyms can be used for any term(s) discussed herein, and no special significance is to be placed upon whether a term is elaborated or discussed herein. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms is illustrative only, and in no way limits the scope and meaning of the present disclosure or of any exemplified term. Likewise, the present disclosure is not limited to various embodiments given herein. Numbering terms such as “first,” “second” or “third” can be used to describe various components, signals or the like, which are for distinguishing one component/signal from another one only, and are not intended to, nor should be construed to impose any substantive limitations on the components, signals or the like.

is a functional block diagram of a full-polarimetric radar according to a first embodiment of the present disclosure. Referring to, the present disclosure provides a full-polarimetric radarincluding a first dual-polarized antenna module, a second dual-polarized antenna moduleand an antenna control circuit.

The first dual-polarized antenna moduleincludes a first polarized antennaand a second polarized antenna. The first polarized antennahas a first polarization port P, the second polarized antennahas a second polarization port P, and polarization directions of the first polarized antennaand the second polarized antennaare orthogonal to each other.

Similarly, the second dual-polarized antenna moduleincludes a third polarized antennaand a fourth polarized antenna. The third polarized antennahas a third polarization port P, and the fourth polarized antennahas a fourth polarization port P. Polarization directions of the third polarized antennaand the fourth polarized antennaare orthogonal to each other.

It should be noted that the first dual-polarized antenna moduleand the second dual-polarized antenna modulecan each be a dual-polarized cavity-backed antenna module. Referring to,is a side view of a dual-polarized cavity-backed antenna module according to the first embodiment of the present disclosure, andare respectively top views of first to fourth metal layers of the dual-polarized cavity-backed antenna module according to the first embodiment of the present disclosure.

As shown in, the dual-polarized cavity-backed antenna modulecan be disposed in a substrate having four metal layers, and dielectric layers and conductive vias for electrical connection can be disposed between two adjacent ones of the metal layers. The dual-polarized cavity-backed antenna moduleincludes a first metal member, a T-shaped metal member, a strip-shaped metal member, a second metal member, a third metal memberand a bottom metal member. The first metal member, the T-shaped metal memberand the strip-shaped metal memberare arranged in a first metal layer M, the second metal memberis arranged in a second metal layer M, the third metal memberis arranged in a third metal layer M, and the bottom metal memberis arranged in a fourth metal layer M. It should be noted that inclusion of the third metal memberis for exemplary purposes only, and the dual-polarized cavity-backed antenna modulecan operate normally without the third metal member. That is to say, the dual-polarized cavity-backed antenna modulecan only include the first metal layer M, the second metal layer Mand the fourth metal layer M.

Referring to, the first metal memberis a rectangular metal member having a first openingand a first strip-shaped slotand a second strip-shaped slotextending outwardly from two opposite sides of the first opening, and circular slots are respectively disposed at ends of the first strip-shaped slotand the second strip-shaped slot. In a top view, the first openingcan be, for example, a rectangle, and two opposite edges of the rectangle in a first direction Dare provided with the first strip-shaped slotand the second strip-shaped slotextending along the first direction D. In addition, the first metal memberfurther has a third strip-shaped slotintersecting with the first strip-shaped slot. The third strip-shaped slotcan be, for example, an L-shaped slot having a first portionand a second portion, but the present disclosure is not limited thereto. The first portionis a strip-shaped slot, which extends along a second direction Dand intersects with the first strip-shaped slot, and a circular slot is disposed at an end of the first portion. The second portionis connected to the first portion, and extends along the first direction Dtoward a direction away from the first opening. The second portionis shorter than the first portion.

The T-shaped metal memberincludes a main sectionand a branch sectionconnected to each other. The branch sectionis disposed in the second strip-shaped slot, and a first feeding terminal FPis disposed at an end of the branch sectionthat is not connected to the main section. It should be noted that the T-shaped metal memberis disposed in the first metal layer Msimilar to the first metal member, but is not connected to the first metal member. That is, an edge of the branch sectionis separated from the edge of the second strip-shaped slotby a predetermined distance. It should be noted that a microstrip-to-T-stub feeding structure is provided in this embodiment to serve as a polarized antenna (for example, a first polarized antenna or a third polarized antenna).

On the other hand, the strip-shaped metal memberis disposed in the third strip-shaped slot, and the strip-shaped metal membercan be, for example, an L-shaped metal member having a first portionand a second portionconnected to each other, but the present disclosure is not limited thereto. The strip-shaped metal membercan only include a necessary component, such as the first portion, which can be, for example, a strip-shaped structure. The third strip-shaped slothas a shape similar to an L-shape, and a first partof the third strip-shaped metal memberextends along the second direction D. A part of the first portionis located at an intersection between the third strip-shaped slotand the first strip-shaped slot. In addition, a circular metal member is disposed at an end of the first portionand is accommodated by the circular slot of the third strip-shaped slot. In addition, the strip-shaped metal membercan be optionally provided with a second portionfor adapting purposes. The second portionextends along the first direction Din a direction away from the first opening, and the second portionis shorter than the first portion. The strip-shaped metal memberhas a second feeding terminal FPdisposed at an end of the second portionnot connected to the first portion. It should be noted that a microstrip-to-slot feeding structure is formed to serve as another polarized antenna.

Referring to, the second metal memberis disposed below the first metal member. The second metal memberis a rectangular metal member having a second openingand a fourth strip-shaped slot, which positionally correspond to the first openingand the first strip-shaped slot, respectively. That is, when the second metal memberoverlaps with the first metal member, projections of the first openingand the first strip slotformed onto the second metal layer Moverlap with the second openingand the fourth strip-shaped slot, respectively, and the first openingand the second openingjointly form a back cavity. In addition, the second metal memberis also provided with circular slots,and circular feeding metal members,respectively located in the circular slots,at positions corresponding to the first feeding terminal FPand the second feeding terminal FP, such that positions where signals feed in can extend to the lower metal layers. It can be reasoned that the second metal memberand the first metal membercan be electrically connected through multiple conductive vias arranged between the first metal layer Mand the second metal layer M, the first feeding terminal FPcan be electrically connected to the circular feeding metal memberthrough one of the conductive vias, and the second feeding terminal FPcan be electrically connected to the circular feeding metal memberthrough another one of the conductive vias.

Referring to, the third metal membercan be selectively disposed below the second metal member. The third metal memberis a rectangular metal member having a third openingand a fifth strip-shaped slot, which positionally correspond to the second openingand the fourth strip-shaped slot, respectively. The third metal memberis substantially similar to the second metal member. The third metal memberis also provided with circular slots,and circular feeding metal members,respectively located in the circular slots,at positions corresponding to the first feeding terminal FPand the second feeding terminal FP, such that positions where signals are fed in can extend to the lower metal layer. The third metal memberand the second metal partcan be electrically connected through multiple conductive vias disposed between the second metal layer Mand the third metal layer M, the circular feeding metal membercan be electrically connected to the circular feeding metal memberthrough one of the conductive vias, and the circular feeding metal membercan be electrically connected to the circular feeding metal memberthrough another one of the conductive vias. It should be noted that the third metal memberis merely an example, and the dual-polarized cavity-backed antenna modulecan operate normally without the third metal member.

Referring to, the bottom metal memberis disposed below the third metal member. The bottom metal memberis a rectangular metal member and has sixth strip-shaped slotsandextending to an edge in the first direction D. The sixth strip-shaped slotsandpositionally correspond to the circular slotsandof the third metal component, respectively, and are used to lead signal feeding portions to the edge of the bottom metal member.

The first metal member, the second metal member, and the third metal memberare all electrically connected to the bottom metal component, and the first opening, the second openingand the third openingjointly form the back cavity. According to tests, the dual-polarized cavity-backed antenna modulecan form a unidirectional radiation pattern above the first metal layer M, and two orthogonal modes can also coexist in the back cavity while the dual-polarized cavity-backed antenna moduleradiate signals in a vertical polarization direction and a horizontal polarization direction. Moreover, an isolation greater than 40 dB can be achieved within a frequency ranging from 56 to 67 GHz.

Referring to,is a top view of the full-polarimetric radar according to the first embodiment of the present disclosure, andis a side view of the full-polarimetric radar according to the first embodiment of the present disclosure. Inand, the full-polarimetric radarcan include two adjacent dual-polarized cavity-backed antenna modules-and-arranged in different directions. Specifically, if a direction along which the first strip-shaped slotand the second strip-shaped slotextend in(i.e., the first direction D) are set as a configuration direction, the configuration directions of the dual-polarized cavity-backed antenna modules-and-are perpendicular to each other.

In addition, as can be seen from, the dual-polarized cavity-backed antenna modules-and-are disposed on the circuit boardand have a back cavity Cand C, respectively. The antenna control circuitis disposed between the circuit boardand the dual-polarized cavity-backed antenna modules-and-. It should be noted that the dual-polarized cavity-backed antenna module-corresponds to the first dual-polarized antenna moduleand has the first polarized antennaand the second polarized antennaand the first polarization port Pand the second polarization port Pcorresponding thereto; in addition, the dual-polarized cavity-backed antenna module-corresponds to the second dual-polarized antenna moduleand has the third polarized antenna, the fourth polarized antenna, and the third polarization port Pand the fourth polarization port Pcorresponding thereto. The antenna control circuitcan be implemented in a form of a chip, and can be electrically connected to the first polarization port P, the second polarization port P, the third polarization port P, and the fourth polarization port P.

Reference is made to.is a schematic diagram of a monostatic radar configuration according to the first embodiment of the present disclosure, andis a timing diagram showing an antenna control circuit controlling the full-polarimetric radar to transmit and receive signals in a time-divisionally duplexing manner according to the first embodiment of the present disclosure. In this embodiment, the first dual-polarized antenna moduleand the second dual-polarized antenna modulecan be disposed adjacent to each other as shown into form a monostatic radar configuration.

The antenna control circuitcan use two mutually orthogonal ones of the first polarized antenna, the second polarized antenna, the third polarized antenna, and the fourth polarized antennaas transmitting antennas, and use another two mutually orthogonal ones as receiving antennas. For example, the first polarization port Pand the third polarization port Pcan be used as signal receiving terminals, and the second polarization port Pand the fourth polarization port Pcan be used as signal transmitting terminals.

Next, the antenna control circuitcan radiate a first transmitting signal and a second transmitting signal at a first time point Tand a second time point Trespectively through two mutually orthogonal transmitting antennas, and receive the first reflecting signal and the second reflecting signal corresponding to the first transmitting signal through two mutually orthogonal receiving antennas, and receive the third reflecting signal and the fourth reflecting signal corresponding to the second transmitting signal.

For example, as shown in, in a transmitting phase, vertical polarization signals V and horizontal polarization signals H can be periodically transmitted at different time points. For example, at the first time point Tin one cycle, the horizontal polarization signal H is transmitted through the first polarized antennacorresponding to the second polarization port P, and at the second time point T, the vertical polarization signal V is transmitted through the fourth polarized antennacorresponding to the fourth polarization port P. Energy of the vertical polarization signal V is represented by Ev, and energy of the horizontal polarization signal H is represented by Eh.

At the first time point T, after the horizontal polarization signal H hits a target object and is reflected, the antenna control circuitcan receive the vertical polarization signal V generated by the reflection through the second polarized antennacorresponding to the first polarization port P, and receive the horizontal polarization signal H generated by the reflection through the third polarized antennacorresponding to the third polarization port Pin a receiving phase. Corresponding scattering parameters of the vertical polarization signal V and the horizontal polarization signal H are Svh and Shh, respectively.

At the second time point T, after the vertical polarization signal V hits the target and is reflected, the antenna control circuitcan receive the vertical polarization signal V generated by the reflection through the second polarized antennacorresponding to the first polarization port P, and receive the horizontal polarization signal H generated by the reflection through the third polarized antennacorresponding to the third polarization port P. Corresponding scattering parameters of the vertical polarization signal V and the horizontal polarization signal H are Svv and Shv.

Therefore, detected reflecting energy Esv and Esh can be obtained by multiplying an incident energy by a scattering parameter matrix, as expressed by the following equation:

It should be noted that the reflecting energy carries information of two polarization directions. Compared with the existing co-polarized radar, the obtained reflected energy Esv and Esh can more accurately describe characteristics of the target object and can even further be used to obtain surface morphology information of the target object.

Referring to,is a schematic diagram of signal processing performed by the antenna control circuit according to the first embodiment of the present disclosure. As shown in, the antenna control circuitcan obtain the scattering parameters Shh and Svh according to the first reflecting signal and the second reflecting signal, and generate the scattering parameters Svv and Shv according to the third reflecting signal and the fourth reflecting signal. Data of these scattering parameters can be fused to obtain a detection result.

In other words, by transmitting signals with polarization directions that are mutually orthogonal through a time-divisionally multiplexing manner, after being reflected by the target object, signals with two different polarization directions can be received in a single cycle. These signals can be fused in a signal processing stage to obtain a reflecting signal with complete information, thereby improving the recognition of targets when applied to various radar-related fields.

Furthermore,is a schematic diagram of a bistatic radar configuration according to the first embodiment of the present disclosure. In some embodiments, in addition to disposing the first dual-polarized antenna moduleand the second dual-polarized antenna moduleat the same location to form a monostatic radar module with a two-transmit-two-receive architecture, the first dual-polarized antenna moduleand the second dual-polarized antenna modulecan also be disposed at different locations to form a bistatic radar module with a one-transmit-one-receive architecture as shown in. The first dual-polarized antenna moduleand the second dual-polarized antenna moduleare arranged to be separated from each other by a predetermined distance, and one of the first dual-polarized antenna moduleand the second dual-polarized antenna moduleserves as a receiving module.

In a second embodiment, the present disclosure further provides a full-polarimetric radar, which can include two or more identical dual-polarized cavity-backed antenna modules but arranged in different directions.is a configuration diagram of a full-polarimetric radar according to a second embodiment of the present disclosure. As shown in, a full-polarimetric radarcan include two dual-polarized cavity-backed antenna modules, a full-polarimetric radarcan include three dual-polarized cavity-backed antenna modules, and a full-polarimetric radarcan include four dual-polarized cavity-backed antenna modules. In addition, the full-polarimetric radars,, andall include the antenna control circuit mentioned in the first embodiment, which is not specifically shown here. Furthermore, as a quantity of the dual-polarized cavity-backed antenna modules increases, a quantity of the antenna control circuits is not limited to one, and each antenna control circuit can be connected to different quantities of dual-polarized cavity-backed antenna modules according to user needs, thereby increasing a flexibility for radar system design.

In addition, in this embodiment, the antenna control circuit can control a feeding signal of each dual-polarized cavity-backed antenna to radiate different types of transmitting signals such as vertical polarization, horizontal polarization, positive 45-degree and negative 45-degree polarizations, right-hand circular polarization and left-hand circular polarization through the dual-polarized cavity-backed antenna modules. In addition to controlling the feeding signal through the antenna control circuit, an arrangement of the dual-polarized cavity-backed antenna modulesmust also be matched.

Taking the full-polarimetric radaras an example, two of the dual-polarized cavity-backed antenna modulecan be arranged in directions perpendicular to each other, and the antenna control circuit can control the first polarized antenna to radiate a vertical polarization signal through the first polarization port (corresponding to the first feeding terminal) of one of the dual-polarized cavity-backed antenna modules, and control the second polarized antenna to radiate a horizontal polarization signal through the second polarization port (corresponding to the second feeding terminal) of the one of the dual-polarized cavity-backed antenna modulein-phase. At the same time, a reflecting signal generated by the vertical polarization signal and a reflecting signal generated by the horizontal polarization signal are received through the first polarized antenna and the second polarized antenna of another one of the dual-polarized cavity-backed antenna module. The time-sharing transmitting and receiving mechanism mentioned in the embodiment allows the full-polarimetric radarto detect characteristics of a target object based on the reflecting signals corresponding to the vertical polarization signal and the horizontal polarization signal, respectively. In addition, the vertical polarization signal and the horizontal polarization signal are not limited to being generated from the same dual-polarized cavity-backed antenna module. As long as the polarized antennas are orthogonal to each other, they can be used to generate the vertical polarization signal and the horizontal polarization signal, respectively. At the time point of generating the vertical polarization signal or the horizontal polarization signal, a set of orthogonal polarized antennas that are not used to generate the transmitting signals can be used to receive the reflecting signals.

is a schematic diagram of a configuration of a full-polarimetric radar for generating positive and negative 45-degree polarization signals according to the second embodiment of the present disclosure. Referring to, the full-polarimetric radar′ can include at least two dual-polarized cavity-backed antenna modulesand. The dual-polarized cavity-backed antenna modulecan be tilted 45 degrees relative to a reference configuration direction Dc. More specifically, the dual-polarized cavity-backed antenna modulecan be arranged, such that a direction Da along which the first strip-shaped slot and the second strip-shaped slot extend is inclined 45 degrees relative to the reference configuration direction Dc, and the dual-polarized cavity-backed antenna moduleis symmetrically arranged with the dual-polarized cavity-backed antenna module. The dual-polarized cavity-backed antenna modulehas a first polarization port Pand a second polarization port P, and the dual-polarized cavity-backed antenna modulehas a third polarization port Pand a fourth polarization port P.

In this structure, the antenna control circuit can generate a first transmitting signal and a second transmitting signal through the first polarization port Pand the second polarization port Pof the dual-polarized cavity-backed antenna module, and the first transmitting signal and the second transmitting signal are a positive 45-degree polarization signal and a negative 45-degree polarization signal, respectively. At the same time, a reflecting signal corresponding to the positive 45-degree polarization signal and a reflecting signal corresponding to the negative 45-degree polarization signal can be received through the third polarization port Pand the fourth polarization port Pof the dual-polarized cavity-backed antenna module.

is a schematic diagram of a configuration of a full-polarimetric radar for generating left-handed circular polarization signals and right-handed circular polarization signals according to the second embodiment of the present disclosure. Referring to, the full-polarimetric radar″ can include at least two dual-polarized cavity-backed antenna modules′ and′ arranged in the same direction. The dual-polarized cavity-backed antenna module′ has a first polarization port Pand a second polarization port P, and the dual-polarized cavity-backed antenna module′ has a third polarization port Pand a fourth polarization port P.

In this structure, the antenna control circuit can generate a first transmitting signal and a second transmitting signal through the first polarization port Pand the second polarization port Pof the dual-polarized cavity-backed antenna module′. Specifically, the antenna control circuit can provide two signals with the same energy and a 90-degree phase difference to the first polarization port Pand the second polarization port P, respectively, so as to excite circular polarization signals through two mutually orthogonal polarized antennas of the dual-polarized cavity-backed antenna module′. When the first polarization port Pis delayed by 90 degrees in phase with respect to the second polarization port P, a right-hand circular polarization signal can be generated. Conversely, when the second polarization port Pis delayed by 90 degrees in phase with respect to the first polarization port P, a left-hand circular polarization signal can be generated. Furthermore, a reflecting signal corresponding to the right-hand circular polarization signal and a reflecting signal corresponding to the left-hand circular polarization signal can be received through the third polarization port Pand the fourth polarization port Pof the dual-polarized cavity-backed antenna module′.

Therefore, through the structures of the full-polarimetric radars ofabove, reflecting energy with information of two polarization directions can be obtained. Compared with the existing co-polarized radar, the obtained reflecting energy can more accurately describe characteristics of the target object and can even further be used to obtain surface morphology information of the target object.

In addition, it is worth mentioning that the antenna control circuit in each embodiment of the present disclosure can include radio frequency front-end components, a digital signal processor, a signal modulation circuit, and a signal processing and analysis circuit. In addition, the antenna control circuit also includes a variety of functional circuits, such as low noise amplifiers (LNA), power amplifiers, mixers, and a transceiver system.

Therefore, the dual-polarized antenna module provided by the present disclosure can select two mutually orthogonal signal feeding points as transmitting terminals and another two as the receiving terminals when transmitting and receiving signals. By transmitting signals with polarization directions that are mutually orthogonal through the time-divisionally multiplexing manner, after being reflected by the target object, signals with two different polarization directions can be received in a single cycle. These signals can be fused in a signal processing stage to obtain a reflecting signal with complete information, thereby improving the recognition of targets when applied to various radar-related fields.

The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching.

The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others skilled in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present disclosure pertains without departing from its spirit and scope.